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(No Model.)

M. J. CHASE.

PIANO SOUNDING BOARD.

Patented July 5, 1881.

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UNITED STATES PATENT OFFICE.

MILO J. CHASE, OE RICHMOND, INDIANA, ASSIGNOR TC CHASE BROTHERS & CO., CF SAME PLACE.

PIANO SOUNDING-BOARD.

SPECIFICATION forming part of Letters Patent No. 243,689, dated July 5, 1881.

Application filed December 520, 1880. (No model.)

To all whom it may concern Be it known that I, MILo J. CHASE, a citizen oftheUnited States, residing at Richmond, Wayne county, Indiana, have invented new and useful Improvements in Piano Sounding- Boards, of which the following is a specification.

My invention has reference to improvements in pianos designed to enhance the sonorous quality, volume, and durability of the tone,

and is adapted especially, though not exclusively, to upright pianos.

Theseimprovementsconsist, first, in the combination of two similar sound-boards arranged,

as above set forth, parallel to and independent of each other, each having a portion of the strings independently bridged upon its convex surface secondly, in the construction and arrangement of the board, whereby a portion 2Q of the same at a point farthest removed from the bridges, and in a line approximately parallel thereto is disconnected from the frame, so as to furnish an exhaust portion for the sound-vibrations, and also to overcome the 2 usual cramped condition of the sound-board of upright pianos.

For the purpose of convenient and comprehensive illustration of my invention, I have shown in the drawings a double soundingboard adapted to an ordinary upright piano,

in which class of instruments the greatest advantages of my improvements, singly or combined, are attained; but the improvements may, with slight modifications in construction,

be applied with benefit to other styles of instruments.

In the drawings, Figure 1 is a front elevation of the sounding-board in the square containing-frame of the piano. Fig.2 is a rear elevation of the same. Figs. 3 and 4 are sections in the planes y y and mm, respectively, of

Fig. 1. I

Similar letters in the drawings and specification refer to the same parts.

In the drawings, A designates the frame of the piano, and B C the two members of a double sounding-board, the member B being the sounding-board where but one is employed, as in the ordinary construction; I) and c, the bridges, respectively attached to the members of the double sounding-board, where such arrangement is employed; and 8 s trebleand bass strings in position, respectively, upon the bridges and frames.

In the construction of upright pianos it is usual to secure the sounding-board to the frame around its entire edge, which construction prevents a proper freedom and distribution of vibrations and produces imperfect tones. This defect I remedy by cutting off the board diagonally at one corner, as shown at E, Figs. 1 and 2, re-enforcing the edge by a brace, 7", glued to its under side, into which the cross-braces a are stepped, as shown. The ends of the brace 0' being secured in the frame at e c, it serves as a bridge for the edge of the soundboard, which is otherwise free at such edge.

In theconstruction shown in the drawings the sounding-board, consistingof the two members B C, is arched uniformly from all points of support to the center, presenting the convex side to the strings, the bridge I) carrying all the strings of the upper register of the piano, and the bridge a the bass-strings, all of which are secured in the usual manner to the iron frame F of the piano by pins at both ends. The bridge I) is seated upon the upper or outer member, B, of the sounding-board in the usual manner; but the bridge 0 is seated upon the lower or inner member, C, of the sounding-board, and projects upward through an opening in the member B a sufiicient distance to carry the bass-strin gs above the treblestrings. The advantages of my invention in this respect may be attained in a degree by 8 seating both bridges upon the upper member of the double board, in which arrangement the augmented resonance due to the use of the double board will still be attained through the sympathetic action of the auxiliary mom I ber; but by seating the bass-bridge on the lower member, and thereby transmitting the vibrations of the two sets of strings primarily to independent members of the soumling-board, a far better effectis produced,and many of the obstacles heretofore existing to a perfect resonance throughout the entire register are overcome. I attribute these obstacles in prior constructions to the fact that the sounding-board is held in too high a state of tension by the presence of all the strings on the bridge for the perfect resonance of low tones, whereas in my invention the upper member is in a properly high tension for the upper tones and the lower member in a state of low tension suitable to the slower vibrations of the bass-strings, While each member aids the other by sympathetic vibration, but without interference.

The two members B and O are constructed as in the ordinary manner, but arched, as speci' lied, and strengthened by flat ribs 4' on the under side of each, extended across the grain of the wood, as shown in Fig. 2, stepped into the containing-frame and edge braces r. The connection with the frame is made in the usual manner, the members B and 0 being held apart by a strip of wood interposed between the same at the edges, but connected at no other points. Both members are constructed in the same manner, and when in position are substantially parallel throughout.

In cutting off the sounding-board at one corner, as already described, thus leaving the board free to vibrate at such part between the points of support 0 c, it is found that such part acts as an exhaust, to which the vibrations lend and at which theypass ofi' without interference, and an increased resonance results therefrom. It will be obvious that this feature is not confined to a double sound-board,

but may be applied to any, whether double or single, arched or flat but the best results are attained with an arched sounding-board secured and braced as shown.

Having described my invention, I claim and desire to secure by Letters Patent- 1. The combination of the two soundingboards, sprung into position as described, and arranged parallel to and independent of each other, and each having a portion of the strings bridged upon its convex surface without further connection or support, the said members being constructed and arranged in the described relation, for the purposes set forth 2. The sounding-board and frame of a square piano, constructed and arranged as herein shown and described, whereby a limited portion of the sounding-board, at one corner farthest remote from the bridges and approximately parallel thereto, is left free and disconnected from the containingframe, as and for the purposes described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

MlLO J. CHASE.

Witnesses:

W. A. PEEBLE, D. W. OoMsrooK. 

